Draft regulator for stove pipes



Aug. 24, 1954 H. L. PUFFER 2,687,256

DRAFT REGULATOiR FOR STOVE PIPES AND THE LIKE Filed Jan. 27, 1951.

INVENTOR.

Patented Aug. 24, 1954 DRAFT REGULATOR FOR STOVE PIPES AND THE LIKE' Harold L. Puffer, Minneapolis, Minn, assignor-of one-third to. Harold T. Lanigan, Minneapolis;

Minn.

Application January 27, 1951, SerialNo. 208,139

. 2 Claims.

This invention, relates to an automatic. draft regulator for chimneys.

It is possible by maintaining a constant draft in thechimney of a unit heater such as a circulating heater to adjustthe burner to produce an optimum fire and produce complete combustion of the: fuel and. eliminate the formation of soot.

It is also necessary to provide a draft regulator for such unit heaters to prevent explosions, under extremeconditions.

It is an object of myinvention to provide an adjustable automatic draft regulator which will maintain a substantially constant stack draft forunit heaters and the like.

More specifically, it is an object to provide a pair of interconnected damper valves, one controlling the flow of. air from the room directly to the stack and the other controlling the updraft through the stack to produce a substantially constant updraft from the firepot into the stack.

Still more specifically, it is an object to provide a stack damper for controllably obstructing the gas flow through the stack and a control. damper interconnected with said stack damper and swingably mounted to permit the flow of air from the room to enter the stack above the stack damper to relieve excessive updraft pressures while simultaneously restricting the flow of gases upwardly through the stack by causin swinging movement of the stack damper.

These and other objects and advantages of the invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like reference characters refer to the same or similar parts throughout the several views, and in which Fig. 1 is a side elevational view of my improved draft regulator as mounted in a conventional stove pipe;

Fig. 2 is an end elevational view thereof;

Fig. 3 is a vertical sectional view showing the stack damp-er in fully opened position and the pressure releasing damper in fully closed position by full lines, and by dotted lines showing the stack damper in completely closed position with the pressure releasing control damper in at least partially open position; and

Fig. 4 is an elevational view of the adjustment indicator.

As illustrated in the accompanying drawings, I provide a stove pipe 6 adapted to be connected to the exhaust outlet of a unit heater such as a circulating heater. The stove pipe 6 is provided with a draft releasing section I intersecting the same at right angles thereto in the form shown and affording communication between the air in the room in which the pipe 6- is located and, the interior of said stove pipe. stack damper 8 is in. the form shown fixed to a substantially horizontally disposed pivot shaft 9 which is journaled. in horizontally opposed apertures formed in the pipe section 6 and is disposed slightly below the lower extremity of horizontal sections 1. A control and draft releasing damper I0 is mounted on a shaft I l disposed along a cord of the circular damper NJ which, in the form shown, is located at a. distance below the upper edge of said damper equal: tov one-fourth of the diameter thereof. This, distance, of course, couldbe. varied by weightin certain portions of the control damper Ill". The: connection between the shaft ll and-:the'damper H3 is constructedto frictionally resist relative oscillation therebetweenby provision, of suitable means such as the tabs I: which are fixed to thedamper it and frictionally engage the-shaft ll. An adjustment indicator I3 is fixed relative tothe damper l6 and frictionally embraces the shaft H in a manner similar to the tabs. l2. and has an indicator panel 13a, disposed outside the pipe section 1 to permit easy viewing thereof. The shafts 9" and H each have a crank arm [4 and I5 respectively fixed thereto and an actuating link l6 interconnects said crank arms asbest shown in Fig. 1-. A pair of stop elements I1 and it respectively limit the swinging movementof the two dampers 8 and Ill.

The following is a description of the operation of my improved draft regulator for chimneys. Whenever the updraft through the stove pipe 6 exceeds a predetermined velocity, thereby exerting more than a predetermined vacuum on control damper It, said damper It will swin inwardly to permit air from the room to pass into the pipe section and release this excessive updraft therethrough. As the damper l U swings inwardly, the crank arm I5 will, of course, swing up and will push the crank arm [4 downwardly and swing the stack damper 8 toward the dotted line position shown in Fig. 3 to restrict the flow of gases upwardly through the pipe section 6. If the updraft through said section 6 is relatively steady and exceeds the predetermined desired draft, the damper in will remain in inwardly swung position and will hold the restricting damper 8 in partially closed position.

The relation between the crank arm I5 and the plane of the control damper It] may be varied by holding the indicator plate l3a and rotating the shaft ll relative thereto against the frictional force exerted thereby and by the tabs l2. If the A draft restricting updraft is extremely strong, the plate l3ct will be shifted in a counterclockwise direction relative to the crank arm l5, and, of course, the crank arm l5 will be shifted clockwise relative to the plate Ba, and if the updraft is relatively weak, the crank arm 15 will be shifted in the opposite direction toward the edge indicated as weak.

It will be seen that I have provided a highly efficient, relatively simple draft regulator for chimneys, stove pipes, and the like in which the draft through the fire pot may be maintained substantially constant regardless of the wind velocity outdoors and the outdoor temperature, by making a relatively simple adjustment. This adjustment permits the angular relation between the stack damper and the control damper to be varied and also permits the arcuate segment through which the arm l5 travels relative to the arcuate segment traveledby the crank arm M to be varied and thereby control the amount of swinging movement of stack damper 8 for each increment of swinging movement of control damper Hi.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departure from the scope of the present invention, which, generally stated, consists in the matter shown, and described, and set forth in the appended claims.

What I claim is:

l. A draft regulator for stove pipes and the like comprising a generally cylindrical stove pipe section having an inner end adapted to be connected with a heating unit and an outer end adapted to be connected to an exhaust stack to discharge the exhaust gases outwardly through said pipe section, a substantially cylindrical draft releasing conduit intersecting anintermediate portion of said pipe section, a generally circular stack damper diametrically journalled in said section for oscillation on a diametrical axis disposed between the connection of the pipe section with the heating unit and the intersection of said draft releasing conduit with said stove pipe section, a generally circular control damper eccentrically journalled in said conduit for oscillation on an axis disposed along a chord thereof, a pair of operating crank arms respectively fixed to said dampers and disposed exteriorly of said pipe section and said conduit, an interconnection link pivotally interconnectig said crak arms, and stop means preventing said dampers swinging through more than 90.

2. A draft regulator for stove pipes and th like comprising a generally cylindrical stove pipe section having an inner end adapted to be connected with a heating unit and an outer end adapted to be conected to an exhaust stack to discharge the exhaust gases outwardly through said pipe section, a substantially cylindrical draft releasing conduit intersectin an intermediate portion of said pipe section, a shaft transversely journalled in said section and extending thereacross, a generally circular stack damper diametrically fixed to said shaft for swinging movement within said section, a crank arm fixed to one end of said shaft exteriorly of said section, a transversely disposed shaft journalled in said draft releasing conduit, and extending thereacross, a generally circular control damper having an adjustable frictional connection with said shaft along a chord of the damper to normally swing therewith and being disposed within said conduit, a crank arm fixed at one end of said shaft exteriorly of said conduit, and a link pivotally interconnecting said two exteriorly disposed crank arms whereby swingin movement of said control damper caused by updraft through said pipe section produces swingin movement of the stack damper, the connection between said control damper and the shaft frictionally connected therewith permitting forcible relative rotation therebetween to vary the angular relation between said crank arm and said control damper to vary the relationship between said two dampers when in extreme open or extreme closed positions, and stop means limiting the swinging movement of said dampers to substantially References Cited in the file of this patent UNITED STATES PATENTS 

